Pineapple heart rot is caused by the oomycete pathogens Phytophthora parasitica and Phytophthora cinnamomi. The fungi infect pineapple plants through irrigation water and rain splash, colonizing the plant roots and basal leaves. Symptoms include yellowing and browning of leaf tips and a soft, watery rot at the base of leaves. Severe infections can spread up the plant stem and rot developing fruit. The disease is managed through use of disease-free planting material, crop rotation, resistant varieties, and fungicide applications.

1. PAT 401
DISEASES OF HORTICULTURAL CROPS
AND THEIR MANAGEMENT (2+1)
ASSIGNMENT ON
HEART ROT OF PINEAPPLE
SUBMITTED BY
KAMALRAJ G
2016037015

2. CONTENTS
• Introduction
• History
• Distribution
• Economic Importance
• Systematic Position
• Symptoms
• Epidemiology
• Etiology
• Mode Of Spread And Survival
• Management

3. INTRODUCTION
• In 1493, Christopher Columbus brought pineapple from South America to Europe. This
fruit was first named "pina" because it looks like large pine cone,later added name
"apple" to denote it as a fruit
• American colonists regarded pineapples as a luxurious treat because of their rarity and
cost.
• A pineapple is the result of many flowers whose fruitlets have joined around the core.
• And also example for CAM plant.
Ananas comosus
Bromeliaceae
2n=50

4. History
• During September to November 2011, heart rot disese of pineapple was found in Ledong and
Wangning of Hainan Province.
• A survey of 150 ha producing areas of pineapple revealed that the fields were affected at an
incidence ranging from 25% to 30%. Infected plants showed water-soaked lesions and soft
rot on the base of heart leaves near the soil surface
• P. nicotianae was previously reported as the causal agent of heart rot of pineapple in Hawaii,
U.S.A
Distribution

5. SYSTEMATIC POSITION
• Kingdom: Fungi
• Phylum: Heterokontophyta
• Class: Oomycota
• Order: Peronosporales
• Family: Peronosporaceae
• Genus: Phytophthora
• Species: parasitica
cinnamomi
• Causal organism Phytophthora parasitica , Phytophthora cinnamomi

6. SYMPTOMS
• Plants of all ages are attacked, but three to four month old crown plantings are most
susceptible.
• Once symptoms become visible, young leaves are easily pulled from the plant, and the basal
white leaf tissue at the base of the leaves becomes water-soaked and rotten with a foul
smell due to the invasion of secondary organisms
• In the field, heart rot disease of young plants can be suspected where there is a change in
the colour of leaves from normal green to yellowish green and browning of the leaf tips.
• The bases of the leaves shown yellowish white rotten area bordered by distinct and
characteristic brown margin.
• The rot extends the stem of the plant producing a soft cheese-like rotting condition.
• The roots of plants are largely destroyed with the result that the plants remain stunted and
fruit formation is delayed or dose not form at all.

7. Pineapple heart rot
caused by Phytophthora spp.
Heart rot of pineapple is
caused by Phytophthora spp
Pineapple heart rot
caused by Phytophthora
parasitica
Pineapple heart rot
caused by Phytophthora
cinnamomi

8. Pineapple heart rot can move up the peduncle
to rot the fruit of susceptible varieties
NORMAL FRUIT HEART ROT AFFECTED FRUIT

9. ETIOLOGY
Aseptate mycelia, inter & intra cellular haustoria.
• Sexual spores – Oospores (oogonium).
• asexual spores – Zoospores and sporangium
• Primary source of inoculum – Oospores & chlamydospores present in
debris.
Secondary source of inoculum – Air & water splash borne zoospores.
MODE OF SPREAD
The fungus inhabits and survive in the soil in the form of oospores.
• The spores spread through irrigation water and rain splash.

10. EPIDEMIOLOGY
Heart rot under warmer and dry conditions is frequently associated with alkaline
soils and poor drainage.
• It is severe in cool, wet soil.
• Temperatute:25 degree C, heavy rains soon after planting leads to heavy
disease incidence.
• Plants of one or two year age are more susceptible
• Mostly ratoon crops are susceptible.

11. MANAGEMENT
Site selection
• Pineapple root rot occurs most frequently in high-rainfall areas with poor soil drainage.
• Drier areas with good soil drainage are preferred because of the reduced chance of root
rot caused by Phytophthora.
Exclusion & sanitation
• An important part of plant disease prevention is to avoid the introduction of
pathogen inoculum to an uninfested area.
• Tools, farming machinery, containers, media, or planting material contaminated with soil
from off-site should be cleaned and disinfested before use

12. Resistant varieties
• To date, no superior pineapple varieties with acceptable resistance to HEART ROT are
available.
• ‘MD-2’, a hybrid of predominantly ‘Smooth Cayenne’ parentage, exhibits the greatest
resistance when environmental conditions favor plant growth, but not when conditions
favor the pathogen.
Disease-free planting material
• Do not transplant pineapple plants displaying symptoms of root or heart rot.

13. BIOLOGICAL CONTROL
• Application of beneficial microorganisms using Indigenous Microorganisms (IMOs) and
Actively Aerated Compost Teas (AACTs) may be beneficial, depending on the site used
and the cost of such practices. Though existing microorganisms compete with
Phytophthora
CHEMICAL CONTROL
• Bordeaux mixture(1%) spray reduces the disease
• Spraying two common systemic fungicides used against Pythium and Phytophthora are
Ridomil (mefenoxam) and Fosphite (phosphonate) are gives good results
Preparation of 1% Bordeaux
mixture (1:1:100)
Copper sulphate-1 kg,
Quick lime- 1 kg,
Water-100 litres

14. References
• Agrios, G. 2005. Plant Pathology. 5th edition. Elsevier Academic Press. San Diego, CA
• Arjunan.G. Karthikeyan, G, Dinakaran ,D. Raguchander,T. 1999 Diseases of
Horticultural Crops, AE Publications, Coimbatore.
• Pathak V.N. 1980. Diseases of Fruit crops –. Oxford and IBH publishing
Co.Pvt.Limited.